This application relates to image sensors, and more particularly, image sensors having color filter layers.
Image sensors are commonly used in electronic devices such as cellular telephones, cameras, and computers to capture images. In a typical arrangement, an electronic device is provided with an array of image pixels arranged in pixel rows and pixel columns. The image pixels contain a photodiode for generating charge in response to light. Circuitry is commonly coupled to each pixel column for reading out image signals from the image pixels.
Image sensors may include a color filter layer having colored elements and clear elements formed above the photodiodes in the array. Colored photoresist may be deposited and patterned to form the colored elements. Clear photoresist may be deposited and patterned to form the clear elements. Light-blocking structures may be provided between these elements to prevent light that is passing through an element for one pixel from entering an element for an adjacent pixel and causing cross-talk. Separate fabrication steps that may be required for forming the colored elements, the clear elements, and the light-blocking structures may cause the manufacturing process to be complicated and costly. Clear photoresist materials may be susceptible to defects and may not provide an ideal transmission profile.
It would therefore be desirable to provide image sensors with color filter layers having improved clear elements.